Gold

Adhesives
« on: January 21, 2019, 12:52:56 PM »
I have a few different Loctite two part adhesives in  cartridges with a dispenser. I tried gluing two pieces of nylon together. I'm using  EA E-30CL which is supposed to bond plastic. I applied the adhesive and clamped the two pieces together. I waited over 48 hours before I unclamped them. I was easily able to break the two pieces apart. I was also able to easily scrape off the adhesive with a razor blade. What did I do wrong?

I didn't do anything special to prepare the surface. I wiped it down with 99% Isopropol. I just read the literature on that adhesive and it said it needs pockets (I forget the wording) for the adhesive to sit in. Should I score the surfaces?

I would also like to start bonding aluminum with adhesive. I figure if they can glue cars together I can glue some metal together. What kind surface prep and adhesive is strongest for aluminum?


hitchhiker

Re: Adhesives
« Reply #1 on: January 21, 2019, 03:21:05 PM »
I used E6000 to bond poypropylene webbing and it is a strong bond a year later.
Very strong smelling stuff so it has to be done out doors.

JohnRoberts

Re: Adhesives
« Reply #2 on: January 21, 2019, 06:00:28 PM »
Detroit has been glueing cars together your years... IIRC 3M is a major supplier.

JR
John Roberts
http://circularscience.com
Tune it, or don't play it...

Gold

Re: Adhesives
« Reply #3 on: January 21, 2019, 06:16:30 PM »
I read some Loctite technical literature. They say you must rough up the surfaces to be bonded. They like sand blasting for plastics and a chemical etch for metal. I'll try the 3M Scotch-Brite wheels I have for the rotary tool. They don't leave residue. Acetone doesn't seem to damage nylon so I'll use that to clean and degrease.

Re: Adhesives
« Reply #4 on: January 22, 2019, 09:39:34 PM »
I second clear E6000. Oliver Archut turned me onto it for building mics, but I’ve ended up using it all over the place.

JMFahey

Re: Adhesives
« Reply #5 on: March 16, 2019, 04:41:22 AM »
There´s plastics and plastics, thousands of them, some can be glued , some can not.

In principle, and until somebody develops a very specific product for it, consider Nylon "ungluable" , at least if parts have to stand significant flexing/twisting.
Design - Make - Service Audio Equipment since 1969.

rackmonkey

Whether you think you can or you think you can't, you're probably right.

Re: Adhesives
« Reply #7 on: April 07, 2019, 08:03:17 AM »
Id avoid hitting it with anything mechanical , theres not really a need ,and it could generate heat and cause slight melting or deformation of the flatness , Nylon is one of the more slippery plastics , your definately going to want to key it up to get good adhesion , Id say make a small sanding block ,lay the nylon flat then rub both surfaces in the same  direction not randomly or in circles , basically so the roughness on both work pieces run parallel and at 90 degrees to the direction you require maximum strenght ,that should  make best use of the extra surface area  you create .

Theres a two part epoxy we use in work , most often its used to secure motor stators in housings , but Ive also used it for potting plastic terminal enclosures/cable entry glands in submersible pumps  , its very liquid ,takes 12 hours to cure , is full of chemical nasty , but sticks like sh!t to  a blanket,
We high temp oven bake motors  , 5 minutes with two gas torches then  a  'ton' lift crane used as a pullers   to get  the stators  out of the  housings , on plastics its hammer and chissel job to get this stuff off . Cover your work area with newspaper or cardboard and use gloves while handling these 'funky' two part mixes , do have a spare rag handy to clean up spills or drops  too.

Gold

Re: Adhesives
« Reply #8 on: April 07, 2019, 02:08:19 PM »
I didn’t realize this would be difficult. I’ve gone to plan B. The reason I wanted to do it  in the first place was that I thought it would be straightforward. Nope.

Marik

Re: Adhesives
« Reply #9 on: April 12, 2019, 01:00:54 AM »
Whenever you need to glue plastics try to avoid using Nylon, Mylar, Delrin, Teflon, Polypropylene, etc. If possible consider Acrylic, PVC, or other 'easy-to-glue' plastics.

Best, M
Samar Audio & Microphone Design

www.samaraudiodesign.com

The Art of Ribbon Microphones


Gold

Re: Adhesives
« Reply #10 on: April 12, 2019, 01:58:41 AM »
I wanted to both glue it and be able to tap it with hand taps. Is there a non conductive material that would work?

I’ve seen acrylic tapped but it is very gummy. I don’t think it’s easy to do. I don’t know about PVC.

Marik

Re: Adhesives
« Reply #11 on: April 12, 2019, 02:28:14 AM »
I wanted to both glue it and be able to tap it with hand taps. Is there a non conductive material that would work?

I’ve seen acrylic tapped but it is very gummy. I don’t think it’s easy to do. I don’t know about PVC.

Acrylic is very easy to tap even with 0-80--we do it all the time. The key is, because of low melting point you need to use a lot of coolant (we do it on CNC compression tapping with flood). If you do it by hand the speed will be nowhere fast enough to heat it up and melt, so you should be fine. Never tried tapping PVC, but do not see why would be any different. Depending on the size of your parts the FR4 should work fine. You could also make it out of Aluminum and anodize it, which will make it non conductive.

Best, M
Samar Audio & Microphone Design

www.samaraudiodesign.com

The Art of Ribbon Microphones

Gold

Re: Adhesives
« Reply #12 on: April 12, 2019, 12:13:09 PM »
Thanks Marik.

I liked mounting PCB’s on aluminum bar stock that attach to the sides of a chassis allowing access from the top and bottom.  The only issue is that the PCB can’t make contact with it.

I’ll give acrylic a shot. It might be too brittle though. I know it has a tendency to crack rather than bend. I can try PVC too.

Both acrylic and PVC are available in lots of shapes and sizes from McMaster so I’ll try those first. I’m looking for a suitable material rather than a specific part.